1. Field of Invention
The present invention relates to a waterproof connector including a waterproof gel through which a terminal is made to pass and, in particular, to a waterproof connector which, when a terminal is made to pass through a gel, can prevent the cutoff gel from sticking to the connecting portion of the terminal.
2. Related Art
Conventionally, as means for sealing off a space between a housing of a connector and a terminal to be guided from the housing, there is sometimes used grease. However, in the grease, there are found some drawbacks to be improved. In particular, the grease will lower in viscosity at high temperatures and thus can flow out of the sealing space to thereby unstabilize the sealed state of the sealing space. Also, once used, the grease becomes difficult to remove, which makes it difficult to inspect and repair the connector.
Further, in this type of sealing structure, instead of the grease, there is sometimes used epoxy-system adhesive. In this case, it is true that a highly reliable sealing structure can be realized, but, after the adhesive is hardened, reuse of the adhesive, especially, reinsertion of the adhesive is difficult.
As a waterproof connector which can eliminate the above drawbacks, for example, there is known a waterproof connector which is disclosed in Japanese Patent Publication Sho.64-63282. Referring here to this waterproof connector, as shown in FIG. 8, the waterproof connector includes a square-frame-shaped rear holder 1 opened on the mutually opposing surfaces thereof which are arranged in parallel to each other; and, on the inner periphery of one opening 3 of the rear holder 1, there is projectingly provided a frame-shaped stopper 5. A plate-shaped base 7 is inserted into the rear holder 1. In particular, the base 7 is stored within the rear holder 1 in such a manner that it is contacted with the stopper 5 and is thereby prevented against removal from one opening 3. In the base 7, there are opened up a plurality of terminal pass-through holes 8 in a lattice manner.
Into the rear holder 1 with the base 7 stored therein, there is inserted a plate-shaped mat seal member (gel) 13 from the other opening 11 thereof. As shown in FIG. 9, the gel 13 is held by a hold projection 15 provided within the rear holder 1 in such a manner that the outer periphery of the gel 13 is in close contact with the inner peripheral surface of the rear holder 1 and one surface of the gel 13 is in close contact with the back surface of the base 7. As shown in FIG. 10, the rear holder 1 is structured such that the other opening 11 thereof can be fitted with the rear portion of a housing 17. In the rear portion of the housing 17, there is opened up a terminal mounting insertion opening 19 which is in communication with a terminal storage chamber. The terminal mounting insertion opening 19 is in alignment with the terminal through hole 9. That is, the terminal mounting insertion opening 19 and terminal through hole 9 are interrupted by the gel 13 which is interposed between them.
To insert a terminal 23 into the thus assembled connector, the terminal 23 with an electric wire 21 connected thereto may be inserted into the terminal pass-through hole 9 of the base 7 from the surface of the rear holder 1 on which side the base 7 is exposed. The terminal 23 passes through the gel 13 while thrusting through the same, and is then mounted into its corresponding terminal storage chamber formed within the housing 17. As a result of this, the outer periphery of the electric wire 21, which has passed through the gel 13, is closely contacted with the gel 13 to thereby be able to seal off the space between the electric wire 21 and housing 17.
According to the above-mentioned waterproof connector, not only there can be prevented the flow-away of the grease caused by the high temperatures, but also there is possible the re-insertion of the terminal which is impossible in the previously-mentioned conventional connector using the epoxy-system adhesive.
However, in the above-cited waterproof connector, the gel is in close contact with the whole periphery of the peripheral edge of the terminal mounting insertion opening. For this reason, as shown in FIG. 11, when the terminal 23 is pressed against the gel 13 and is made to pass through the gel 13 while thrusting through the same, part of the gel, which exists on the pass-through hole exit side and is in close contact with the inner wall surfaces 25 of the housing 17, loses all means of escape, so that such part of the gel 13, together with the terminal 23, is caused to expand out and pushed into the terminal mounting insertion opening 19.
As a result of this, such expanded portions 13a are cut off from the gel 13 and, as shown in FIG. 12, the expanded portions 13a turn out into cutoff crumbs 13b: that is, there is a possibility that the cutoff crumbs 13b, together with the terminal 23, can invade the terminal storage chamber 27. In this case, when the present connector is connected with its mating connector, there is a fear that the cutoff crumbs 13b can invade between the contacts of the mutually connected terminals to thereby cause poor conduction between them.